Pneumatic coupling



" UNITED :STATES PATENT OFFICE! WALTHEB LINDNER, F DUSSELDORF-GRAIENBEBG, GERMANY, ASSIGNOR TO THE FIRMHOHNZOIIIII-ERNAKTIENGESELLSCHAFT FUR LOKOMO'I'IVIBAU, 0] 15118831]-nonr-Gaunmmne, emm' I rn'mms'rrc courrrne Application flied December 21,1927, Serial No.

My invention relates to improvements in pneumatic friction-clutches andhas for its primary object to provide a construction of clutch whichwill be capable of transmitting 5 large powers with efliciency andreliability.

The invention further consists in the provision of improved coolingmeans and inmeans for preventing leakage.

A further object of my invention consists therein that an efficientcooling by air is pr0.-

vided for the friction discs of the coupling for the purpose of.properly dissipating the heat which is generated in sli pmg condition ofthe coupling. In-the st place'according to this invention the twofrictional coverings or, groups of' laminae do not contact with eachother along their entire faces,

this being accomplished bydividing said surfaces into a great number ofisles, which may 2 be eflfectively touched on all of their sides by thecooling air. The effect of suction exerted on the cooling airvwill begreatl enhanced by the channels which are provi ed between said severalisles. Air is supplied to the laminae of the friction-coupling byfurther amply dimensioned channels so that no stowing-up of the air cantake place in sald'channels. For. this pur ose the hub ofthe respec-'tive couplin mem er is provided with extensions of .-shapedcross-sectional conformation. From here the air will be supplied to thefrictional coverings or laminae o the coupling in evenquantities inaccordance with the uniformconditions of resistance existing at saidfrictional coverings or laminae. Theaccompanying drawing represents anexample of the construction 0 the pneumatic friction coupling accordingto this invention. Inthe drawings. 1 40 Fig. 1 is a longitudinal sectionthrough the new coupling, while 1 h Fig. 2 is a cross-section takenalongthe linew-aofFig. 1. w Referrin now more particularly to thedrawings, is a shaft to which the hub B of one. of the members of thecoupling is keyed, said hub carrying the one group of la'minaa D Kes Eare provided in order to revent rotation of said laminae around the ubB. The hub C'with the bell-shaped 241,717, andjn Germany December 21,1928 extension is loosely mounted on the shaft A and after throwing-inthe cou ling the said hub will rotate together with said shaft.

The laminae D of the other group are prevented from rotating within saidbell-shaped extension b means of keys F. Both groups of laminae 1 and Dare enclosed by the bellj shaped extension of the hub C. A ring isconnected to said hub C, which by means of projecting parts H engagingwith proper recesses provided in the pressure plate J will serve as aguide for the latter. The bellshaped extension of the hub C isfurthermore provided with an arched lateral wall or plate K forming abearing for the tube L which serves for supplying pressure air to thecoupling, said bearing (comprising furthermore two ball-bearings M. Thetube L is kept fixed, and the said bearing is rotat able together withthe bell-shaped clutch member C. The bore surface of thehub .of

the plate K and the ooacting exterior surface of the tube L are providedwithrecesses which contain a packing medium-such as oil. The pressureair is fed through the tube L to an expansible annular pressure cham-vber the side walls of which are formed by the plates J and'K and theouter wall of which consists of an expansiblecorrugated tube N the twoends of whichare tightly 0on nected with the plates J andK. The tube Lcommunicating with the annular pressure chamber is axially arranged tosaid-chamber which is held tightly closed by the pacldng means at thejunction of the tube L and the hub of the plate K. Byaction of theairpressure the pressure plate J will be moved towards the laminae D andD said. mem- As the pressure plate 1y to thepressure plate J which isprevented from rotation by the projections H. The friction taking placein the two bearings O and P will therefore be very small. For 5 carryin'back the pressure plate J into its origlna positions after removal ofthe pres-.

sure air and for disengaging the coupling, the spring action of themembrane N will be suflicient. In order to reduce the weight of thepressure plate J the latter is made, as above indicated, of conicalform, this form simultaneously providing for sufiicient rigidity of saidpressure plate.

It is important to provide an efficient cooling for the frictionalmembers of the cow pling, in order to keep the same permanently in oodworking condition and in order to avold the production of excessive heatin case j of frequently. repeated slipping of the couplin This iseffected by the channels Q whi%1 are provided on the hub B thecrossection of these channels being shown in Fig.

2. By these channels T-shaped extensions or spokes R will be produced onsaid hub B. The air flows throu h the'recesses in plate J into thechannels 5 and then radially outward through the clutchiplates. Thechannels Q are made of relatively large cross-section thus permittingthe pressure-air to be uniformly distributed over all laminae l) and DThe air which is carried to said laminae will be caused to whirl aboutthe shaft A and to be thrown in outward direction by centrifugal force.The air will be effectively distrlbuted and carriedinto the intersticesbetween the several laminae D and D As the additional frictional membersD forming other, even in case the coupling is thrown.

1n; air may therefore always pass around ing for'the latter. On theother hand the interstices which are provided between the laminae willcontribute to enhance the effect of suction exerted on the cooling air.The air may pass to the outside of the coupling through apertures Sprovided on thebellshaped extension of the hub C.

I claim: .1. In a pneumatic friction clutch the combination of adrivingmember, a coaxial A driven member, each of said members carrying a setof friction discs, a centrally arranged and-axially displaceableressureglateadapted to bring the ts o "friction iscs into frictionalengagement with each other, said pressure-plate forming one side 7 wallof a t-ight pressure-chamber. a centrally arranged and axially immovableplate forming the "other side wall, a longitudinallyexpansiblecorrugated tube of relatively small.

said laminae and provide an effective 0001- diameter forming the outerwall of thesaid pressure-chamber, and apertures in the saidpressure-plate, on the outside of the pressure-'' chamber, suchapertures leading cooling air to the discs. 2. In a pneumatic frictionclutch the com- A bination of a shaft, a bell-shaped clutch memberrotatably mounted on said shaft, a second 'clutch-member fast on saidshaft, each of said members carrying a set of friction discs, acentrally arranged plate fixed to the flange of the saidbell-shapedclutch-member and forming a side wall of'a pressure-chamber,an axially displaceable actuating pressureplate forming the other'sidewall, a lon tudinally expansible corrugated tube of re atively smalldiameter forming the outer wall of said pressure-chamber, and aperturesin the said two plates, on the outside of the pressure-chamber, suchapertures leading 5 cooling air to the friction discs. I I

3. In a pneumatic friction clutch the combination of a. shaft, abell-shaped clutchmember rotatably'mounted on said shaft, a secondhub-like clutch member fast on said 0 shaft, each of said memberscarrying a set of friction discs, a centrallyarranged plate fixed to theflangecof the bell-shaped clutch member and forming aside wall of anex'-- pansible pressure-chamber, an axially displaceable actuatingpressure-plate forming the other side wall and an axially ex ansiblecorrugated tube of relatively small iameter forming the outer wall ofsaid pressurechamber, and apertures in the said two plates, on theoutside of thepressure-chamber, such apertures communicating withcavities in. the said hub-like clutch member to lead cooling air tothe-friction discs.

4. In a pneumatic friction clutchthe com- 5 bination of a shaft, abell-shaped clutch member rotatably mounted on said shaft, a secondhub-like clutch member fast on said shaftfeach of said memberscarrying aset a of friction discs, a centrally arranged plate fixed to the flangeof the bell-shaped clutch member and 'forming a side wall of anexpansible pressure-chamber, an axially displaceable actuatingpressure-plate forming the other side wall and an axially expansible 116corrugated tube of relatively small diameter forming the outer wall ofsaid pressurechamber, and apertures in the said two plates,

on theoutside of the pressure-chamber, such apertures communicating withair ducts 120 provided between adjacent friction idiscs through theintermediary of cavities in the said hub-like clutch -member.

5. In a pneumatic friction clutch the com-" bination of ashaft, a'bell-shaped clutch 5 member rotatably mounted on said shaft, a secondhub-like clutch member fast on said shaft, each'of said members carryinga set of friction discs, a centrally arranged plate fixed to the flangeof the bellshaped clutch vsure-chamber, a pressure-air supply member andforming a side wall of an expansible pressure-chamber, an axiallyexpansible'corrugated tube forming the outer wall and an axiallydisplaceable actuating pressure-plate formin the other side wall of saidpressure-cham er, thesaid pressureplate having a central extensionguided in a central bore of the said shaft. 7 a

6. In a pneumatic friction clutch the com- 1 bination of a shaft, abell-shaped clutchher, a pressure-air supply tube leading through acentral hub of the said'axially immovable side wall, packing meansprovided between said hub and said tube and an addition'al bearing forthe supply tube, said In testimony whereof I afiix my signature.

' WALTHER LIN DNER.

provided between said hub and said tube. v

7 In a pneumatic friction clutch the combination of a shaft, abell-shaped clutchmember rotatab ly'mounted on said shaft, a

' second clutch-member fast on said shaft, each of said members carryinga set of friction discs, a centrally arranged and axially immovableplate fixed to the flange of the said bell-shaped clutch-member andforming a side wall of a pressure-chamber, an axially displaceableactuatin pressure-plate forming the other side wall, a longitudinallyexpansiblecorrugated tube of relatively small diameter-forming the outerwall of said prels 40 leading through a central hub of the axiallyimmovable plate, packuig means provided between said hub and" said tube,and an additional bearing for the supply tube, said bearing beingpositioned on the outside of 4 5 the labyrinth-pw I 8. In-a pneumaticfriction clutch the com- *.bination of a shaft,a bell-shaped clutch;

member rotatably mounted on said shaft, a;

second hub-like clutch fmember fast on said shaft, a centrallyarranged'plate fixed to the flange of the 'said bell-shaped clutchmemher and forming an axially immovable side wall of an axiallyexpansible pressure-cham-- ber, a pressure-air supply tube leadingthrough a central hub. of the saidaxially immovable side wall, andpacking means provided between said hub'and said tube.

9. In a pneumatic friction clutch the combination of .a shaft, abell-shaped clutch member rotatably'mou'nted on said shaft, a

second hub-like clutch member fast on said shaft, a centrally arrangedplate fixed to the flange'of "the said bell-shaped clutch member andforming an axially immovable side 5 wall of an axially expansible prewure-chambearing-being positioned on the outside of .th-epacking means.

